The aim of this paper is to provide a systematic study of the functioning of wh-pronouns. The idea of their unity in the 'Tongue' Domain stands for us as a major requirement. The occurrence of whoever, whatever, whichever, and wh (o)/(ich) with their antecedents results from a systematicity built in the deep structure of language. The approach adopted in this study opposes a simple description of the linear sequencing of words in language to the potential significate in the Tongue domain, because the observable or the effects of sense have consequence on the mental representation of language. The system of wh-pronouns is mainly based on two concepts: 'predicativity' and 'virtuality'. These two constructs will be shown to underly the functioning of the wh-pronouns in English.